This invention relates to closed water systems and more specifically to an improved diaphragm assembly as used in an expansion tank forming a part of the system.
Expansion tanks, as used in domestic water systems, provide an air surge chamber that accounts for variations in pressure within the system. Tanks of this type are divided into chambers by a flexible diaphragm wherein gas under pressure is contained in one chamber while system water is contained in the other. The water chamber is connected to the system and changes in pressure are created by the increase and decrease associated with water volume usage in the normal cyclic operation of the system. Expansion tanks of this general type are described in U.S. Pat. Nos. 2,695,753 and 3,035,614 to C H Kirk, Jr., and 2,815,152 to L E Mills.
Recent improvements in tank design include glass or plastic liners that makes assembly of the tanks as taught by the prior art, more difficult, especially as it relates to positioning and sealing of a flexible diaphragm within the tank and closure of the tank without damaging the diaphragm seal and/or liner.
Therefore, it is a primary object of this invention to provide a diaphragm assembly that is easily installed, facilitates tank assembly, and provides a positive seal in either lined or unlined expansion tanks.